Improving Fire Safety Systems Based On Internet Of Things And Deep Learning

Structure fires are one of the main concerns for fire safety systems. The actual fire safety of a building depends on not only how it is designed and constructed, but also on how it is operated. Computational fluid dynamics software is the current solution to reduce the casualties in the fire circumstances. However, it consumes hours to provide the results in some cases that makes it hard to run in real-time. It also does not accept any changes after starting the simulation, which makes it unsuitable for running in the dynamic nature of the fire. On the other hand, the current evacuation signs are fixed, which might guide occupants and firefighter to dangerous zones.<div><br><div>In this research, we present a smoke emulator that runs in real-time to reflect what is happening on the ground-truth. This system is achieved using a light-weight smoke emulator engine, deep learning, and internet of things. The IoT sensors are sending the measurements to correct the emulator from any deviation and reflect events such as fire starting, people movement, and the door’s status. This emulator helps the firefighter by providing them with a map that shows the smoke development in the building. They can take a snapshot from the current status of the building and try different virtual evacuation and firefighting plans to pick the best and safest for them to proceed. The system will also control the exit signs to have adaptive exit routes that guide occupants away from fire and smoke to minimize the exposure time to the toxic gases<br></div></div>

Improving Fire Safety Systems Based On Internet Of Things And Deep Learning

Structure fires are one of the main concerns for fire safety systems. The actual fire safety of a building depends on not only how it is designed and constructed, but also on how it is operated. Computational fluid dynamics software is the current solution to reduce the casualties in the fire circumstances. However, it consumes hours to provide the results in some cases that makes it hard to run in real-time. It also does not accept any changes after starting the simulation, which makes it unsuitable for running in the dynamic nature of the fire. On the other hand, the current evacuation signs are fixed, which might guide occupants and firefighter to dangerous zones.<div><br><div>In this research, we present a smoke emulator that runs in real-time to reflect what is happening on the ground-truth. This system is achieved using a light-weight smoke emulator engine, deep learning, and internet of things. The IoT sensors are sending the measurements to correct the emulator from any deviation and reflect events such as fire starting, people movement, and the door’s status. This emulator helps the firefighter by providing them with a map that shows the smoke development in the building. They can take a snapshot from the current status of the building and try different virtual evacuation and firefighting plans to pick the best and safest for them to proceed. The system will also control the exit signs to have adaptive exit routes that guide occupants away from fire and smoke to minimize the exposure time to the toxic gases<br></div></div>

Adaptive Forest Fire Spread Simulation Algorithm Based on Cellular Automata

The popular simulation process that uses traditional cellular automata with a fixed time step to simulate forest fire spread may be limited in its ability to reflect the characteristics of actual fire development. This study combines cellular automata with an existing forest fire model to construct an improved forest fire spread model, which calculates a speed change rate index based on the meteorological factors that affect the spread of forest fires and the actual environment of the current location of the spread. The proposed model can adaptively adjust the time step of cellular automata through the speed change rate index, simulating forest fire spread more in line with the actual fire development trends while ensuring accuracy. When used to analyze a forest fire that occurred in Mianning County, Liangshan Prefecture, Sichuan Province in 2020, our model exhibited simulation accuracy of 96.9%, and kappa coefficient of 0.6214. The simulated fire situation adapted well to the complex and dynamic fire environment, accurately depicting the detailed fire situation. The algorithm can be used to simulate and predict the spread of forest fires, ensuring the accuracy of spread simulation and helping decision makers formulate reasonable plans.

Development of Training Scenario Content for On-Site Commanders through Analysis of Response Failure Factors

The aim of this study was to develop training content to strengthen the response capabilities of on-site commanders in actual fire sites. By analyzing past fire cases with insufficient fire responses during firefighting activities, it was determined that analyzing the causes through fire investigations and their corresponding responses is an important step. In addition, although identical fire occurrence situations cannot be reproduced, the causes and responses could be categorized similarly. In this study, the various problems occurring frequently during firefighting activities and factors affecting the response failures were analyzed according to the main causes of fires by building type. Thus, various training scenarios were developed and applied based on the above considerations.

Numerical simulation of the experimental behavior of RC beams at elevated temperatures

The danger of fire is present always and everywhere. The imminent danger depends upon the actual type and length of fire exposure. Reinforced concrete structural members are loadbearing components in buildup structures and are therefore at high risk, since the entire structure might potentially collapse upon their failure. Thus, it is imperative to comprehend the behavior of reinforced concrete members at high temperatures in case of fire. In this study, the mechanical properties of concrete exposed to high temperatures were experimentally determined through the testing of 27 concrete cylinder starting at room temperature and increasing up to 260 °C. The concrete material behavior was implemented into the ABAQUS software and a finite simulation of reinforced concrete beams exposed to actual fire conditions were conducted. The finite element models compared favorably with the available experimental results. Thus, providing a valuable tool that allows for the prediction of failure in case of a fire event.

The concept of calculating the actual limit of fire resistance of building structures

Проведен краткий анализ понятий, связанных с расчетом пределов огнестойкости строительных конструкций. Дано определение термина «фактический предел огнестойкости», которое отсутствует в нормативных документах по пожарной безопасности. Отмечено, что это связано с использованием на практике значений пределов огнестойкости, определенных для стандартных температурных режимов пожара, в то время как на практике указанные температурные режимы, как правило, отличаются от стандартных. Предложена концепция определения фактического предела огнестойкости, основанная на моделировании воздействия на строительную конструкцию температурного режима реального пожара (например, с помощью программного комплекса FDS 6). The brief analysis of definitions connected with estimation of fire resistance limits of building structures is conducted. There is given the determination of term “actual fire resistance limit” that is absent in fire safety normative documents. It is caused by practical application of the fire resistance limits determined for standard temperature regimes of fires only, but at the same time the temperature regimes of real fires as a rule differ from the standard regimes. There is proposed the method for determination of the actual fire resistance limit based on the modeling of influence of the real fire temperature regime on buildings structures. This modeling can be made by an application of CFD methods (for example, with the help of FDS 6 software complex). The required reliability of the building structure is considered. The proposed method can solve the problem of practical applicability of certain structural unit during designing buildings and structures, for which the use of the resistance limits obtained for the standard fire temperature regimes can lead to unjustified economic expenditures without an appropriate elevation of fire safety level of the object.

Some Approaches to Developing a Test Method for Determining the Actual Fire Resistance Limit of Façade Translucent Structures

Based on the analysis of modern construction of high-rise buildings with façade translucent structures (FTS), it was established that the actual fire resistance limit of FTS for high-rise buildings should be assessed. The criterion for loss of fire resistance of a translucent façade is the collapse or fall-out of fragments of the translucent façade filling that contribute to the spread of fire in the building. By analyzing the experience of tests carried out fragments of buildings with FTS with simulated thermal and/or fire (flame torch) effects, the following factors are taken into account: wind loads with variable directions of air flows; access of fire-fighting and rescue units, etc. During full-scale FTS tests, a possible scenario of fire development is simulated, taking into account the fragment and features of the specimen, the fire load that affects the development of fire along the façade, the structural design of the FTS, – glass (conventional and fireresistant) and structural elements. The authors suggest that in order to ensure fire safety of high-rise buildings with FTS the fire-resistance limit assessment should be carried out on fragments of buildings with a simulation of thermal and/or fire impact, which is close to the real conditions.

INVESTIGATION AND MANAGEMENT OF FIRE RISKS AT SITES WITH APPLICATION OF TRANSLUCENT BUILDING STRUCTURES

On the base of analyses on the development of the construction industry as well as fires occurring in Kazakhstan, the article justifies the areas of fire prevention related to technical regulation that is the certification of materials, construction structures and engineering systems. The translucent building structures have increasing application in modern construction techniques. For such structures, the most vulnerable indicator is the fire resistance limit. A technical solution is offered to increase this indicator by using water irrigation. On the base of existing international and national regulatory documents, a number of methods has been developed for experimental determination of the actual fire resistance limit by cooling of structures with water in case of fire. Large-scaled fire researches have been carried out to determine the actual limit of fire resistance of the translucent partition made of tempered glass "Float" with the thickness of 12 mm, M1 grade both in the presence of water irrigation and in the absence thereof. The tests were carried out under standard and actual fire conditions. Optimal parameters of water irrigation are determined. On the base of research results, it is proposed to improve the construction standards in this field as well as methodological documents in the field of certification tests.

Evaluation of fire-retardant effectiveness of coatings for steel structures

Представлены результаты анализа экспериментальной и аналитической оценки огнезащитной эффективности покрытий для стальных конструкций. Обобщены данные многолетних исследований по определению зависимостей от температуры таких теплофизических характеристик, как теплопроводность и теплоемкость. Разработана структурно-методологическая схема выбора огнезащитных покрытий для стальных конструкций в целях обеспечения нормативных требований по огнестойкости. Проведены экспериментальные исследования по определению огнезащитной эффективности терморасширяющихся покрытий на эпоксидной основе при воздействии температурного режима горения углеводородов. Рассмотрен вопрос о гармонизации методики экспериментальной оценки огнезащитной эффективности средств огнезащиты для стальных конструкций с действующими европейскими нормами. Установлены критерии выбора пассивной огнезащиты, зависящие от области применения способов огнезащиты. Steel structures have high strength, relative lightness and durability, but when exposed to high temperatures in a fire, they deform, lose stability and load-bearing capacity. The collapse of load-bearing steel structures can occur in 10-15 minutes after the fire start. The actual fire resistance limit of structures can be increased by using the active and passive fire protection systems. The use of the active system for increasing the actual fire resistance limit is not provided in the regulatory documents. Passive fire protection is a complex of technical solutions including the use of non-flammable materials and bulging compounds. It is also an integral part of the building structure that ensures the required fire resistance limit. Assessment of fire resistance of building structures of residential, public, warehouse and industrial buildings is carried out taking into account the temperature regime (cellulose) of a standard fire. At oil and gas, petrochemical enterprises as well as at oil production platforms fires can occur at combustion of various hydrocarbon fuels which are characterized by a rapid temperature increase to 1100 °C. In this case, in accordance with GOST R EN 1363-2-2014, the temperature regime of hydrocarbon combustion is used to assess the fire resistance of building structures. The fire-retardant effectiveness of fire protection means for steel structures is determined by the heating time of the standard I-shaped column without applying a static load on the sample to the average “critical” temperature of the steel of 500 °C. Materials used for fire protection of steel structures must have a good thermal insulation ability, which is estimated by the coefficient of thermal conductivity. When heated to high temperatures, the thermal conductivity coefficient of fire-resistant materials varies depending on their composition and temperature. Based on the analysis of research to determine the fire-retardant effectiveness of fire protection means for steel structures there was developed a structural and methodological scheme that allows to make a choice of fire protection. Currently, as a fire protection there are widely used intumescent paints and thermo-expandable coatings. Taking into account the lack of knowledge of the influence of long-term operation and a large number of other technological factors on the fire-retardant effectiveness of coatings of steel structures covered with intumescent paints, it would be right to limit the use of such type of fire protection for load-bearing structures contributing to the overall sustainability of buildings with a required fire resistance of R 30. For fire protection of steel structures of oil and gas facilities located in the open air, in severe climatic conditions and exposed to aggressive environments there is successfully used a thermo-expandable two-component epoxy-based coating. The analysis of experimental data showed that the use of epoxy-based coatings is suitable for metal structures in the open air. In closed rooms the epoxy intumescent coating should not be used because at high temperature in a fire it ignites with toxic combustion products release.

Flow-Velocity and Pressure Fitness of Sprinkler Pipes Applied with Orifice

The sprinkler design of buildings is based on the top-floor end sprinkler head, and the water flow rate and pressure are designed. When the floor is close to the bottom floor pump, unnecessary flow rate, pressure, and flow velocity become inevitable. Moreover, when the sprinkler head is opened to less than the actual fire time reference number, the excessive flow rate, flow velocity, and pressure are generated. Therefore, the damage to the water or droplet particle becomes less significant, which can be disadvantageous for efficient fire suppression. Therefore, in this study, we applied an orifice to the branch pipe of each sprinkler head to decrease the excessive flow rate, flow velocity, and pressure. It was confirmed that the design value was maintained for each floor of the high building. When the orifice was applied, the flow rate and positive well were reduced, which could prevent overpressure.